Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: empty-string honors a partial-update for sensitive headers, and `shared` toggling migrates the connection between personal and team scope. This is real value beyond annotations, though it doesn't fully explain mutation consequences for other fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the core purpose, then the two highest-value behavioral notes. No filler; each sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given annotations already cover the safety profile and there is no output schema to explain, the description covers the tricky non-obvious behaviors well. It stops short of addressing auth_method/server_url change semantics or name uniqueness, but nothing critical for calling it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 17%, so the description must carry meaning. It adds real semantic detail for `headers` (empty-string keep semantics) and `shared` (scope migration), but leaves name, server_url, auth_method, and connection_id unexplained beyond the schema's bare type/format.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Update an existing connection'), which cleanly separates it from createConnection, deleteConnection, and getConnection siblings by verb. It does not, however, explicitly name which sibling it replaces or how it differs from e.g. updateCredential/updateSecret.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage through its semantics but gives no explicit when-to-use vs alternatives guidance (e.g., updateConnection vs deleteConnection+createConnection, or when to prefer update over create). Usage context is inferable from the name but not spelled out.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.